If I didn’t know better now, eVent DVL waterproof breathable fabric (introduced last autumn) would remind me of yet another diet fad (burn that fat!…eliminate that sweat!). Unfortunately such attempts at worn humor will definitely fall with a wet splat like some hapless trail runner tripping in a mud puddle as eVent DVL actually works just about as well as they say it does.
Product literature claims eVent DVL is “air permeable.” That’s a bit of liberated language, as nearly any waterproof breathable fabric is “air permeable” to one degree or another, but usually not much. Try the bubble test. Grab a hunk of your favorite shell’s fabric, twist and seal until you get a bubble of air in the fabric. With some jackets the bubble will push out through the fabric fairly easily; others it’ll feel like you’re trying to push air out of a plastic bag. Bubble test the eVent DVL. Air passes through the fabric so easily you can barely get a bubble to hold.
What’s that mean? Most “waterproof breathable” fabrics “breathe” by shedding water vapor, but they don’t pass much air. You’ll feel a difference in comfort between your hardshell and your softshell. The hardshell will sweat up faster. Holy grail of fabric design is to cook up something that feels like the breathability of a softshell, but won’t let water in when it’s snowing cat globs. Does eVent DVL do it?
Westcomb sent over their new Focus LT Hoody which has about as much mass as a meth addict’s left bicep and is indeed made from eVent DVL. Perfect. Just the kind of shell I like to use in our relatively dry Colorado climate.
So I tested. First, be aware that this fabric is not designed as an Amazonian rain protection system. “Unlined garments…for light outdoor and aerobic activities” is how the official tag reads. In other words, a workout jacket that’ll keep you more comfortable than trudging in a drizzle wearing a baselayer top (yum, feel that chill!). My test was simple. I did a 45 minute heavy aerobic hike in 40 degree temps with just a baselayer under the Focus, zipped up tight. I’ll testify that yes, this stuff really does breathe like crazy. I sweated up a bit simply due to less natural airflow around my torso, but was amazed at the total lack of the proverbial “jungle air” feeling you get from heating up in a typical hardshell.
In terms of water resistance, I found the Focus LT to be similar to other thin and ultra breathable water resistant membranes. It’ll keep you dry in a brief downpour, is surprisingly waterproof for being so lightweight, but a lengthy day in wet snow or constant rain will eventually cause wet-through in areas such as underneath your backpack straps. That’s not an insult to eVent, it’s just what is. Remember, if you’re doing high output activities the breathability of these fabrics is far more important than their ultimate water resistance — just don’t expect it to be the garment for sitting through an all-night bivvy in the rain.
Oh, and about the Focus LT Hoody? They should sell this thing at Victoria’s Secret. It would fit just fine on the garter rack. That’s how little of it there is. No waist drawstring. No pit zips (it breathes!). One teeny breast pocket the size of Gerber Baby’s pinkie. Front height is a bit short (rear hem drops a few inches lower), but with “full cut” the jacket fits over my medium weight puffy, and has a helmet compatible (but tight) hood as well. Yep, look for this in your favorite catalog (and I’m not talking REI). Mass: 9.7 ounces 274 grams. Wow.